/*
Algorithm Name: Keccak
Authors: Guido Bertoni, Joan Daemen, Michaël Peeters and Gilles Van Assche

This code, originally by Guido Bertoni, Joan Daemen, Michaël Peeters and
Gilles Van Assche as a part of the SHA-3 submission, is hereby put in the
public domain. It is given as is, without any guarantee.

For more information, feedback or questions, please refer to our website:
http://keccak.noekeon.org/
*/

#include <stdio.h>
#include <string.h>
//#include "brg_endian.h"
#include "displayIntermediateValues.h"
//#include "KeccakNISTInterface.h"
//#include "KeccakF-1600-interface.h"
//#include "KeccakF-1600-interface.h"



#include "costants.h"

void displayRoundConstants(FILE *f);
void displayRhoOffsets(FILE *f);

//#include "KeccakF-1600-int-set.h"


typedef unsigned char UINT8;
typedef unsigned long long int UINT64;

#define nrRounds 24
UINT64 KeccakRoundConstants[nrRounds];
#define nrWords 25
unsigned int KeccakRhoOffsets[nrWords];

void KeccakPermutationOnWords(UINT64 *state);
void theta(UINT64 *A);
void rho(UINT64 *A);
void pi(UINT64 *A);
void chi(UINT64 *A);
void iota(UINT64 *A, unsigned int indexRound);

/*
void fromBytesToWords(UINT64 *stateAsWords, const unsigned char *state)
{
    unsigned int i, j;

    for(i=0; i<(KeccakPermutationSize/64); i++) {
        stateAsWords[i] = 0;
        for(j=0; j<(64/8); j++)
            stateAsWords[i] |= (UINT64)(state[i*(64/8)+j]) << (8*j);
    }
}

void fromWordsToBytes(unsigned char *state, const UINT64 *stateAsWords)
{
    unsigned int i, j;

    for(i=0; i<(KeccakPermutationSize/64); i++)
        for(j=0; j<(64/8); j++)
            state[i*(64/8)+j] = (stateAsWords[i] >> (8*j)) & 0xFF;
}
*/

void KeccakPermutation(unsigned char *state)
{
/*
#if (PLATFORM_BYTE_ORDER != IS_LITTLE_ENDIAN)
    UINT64 stateAsWords[KeccakPermutationSize/64];
#endif
*/
    //displayStateAsBytes(1, "Input of permutation", state);
//#if (PLATFORM_BYTE_ORDER == IS_LITTLE_ENDIAN)
    KeccakPermutationOnWords((UINT64*)state);
/*#else
    fromBytesToWords(stateAsWords, state);
    KeccakPermutationOnWords(stateAsWords);
    fromWordsToBytes(state, stateAsWords);
#endif*/
    //displayStateAsBytes(1, "State after permutation", state);
}

void KeccakPermutationAfterXor(unsigned char *state, const unsigned char *data, unsigned int dataLengthInBytes)
{
    unsigned int i;

    for(i=0; i<dataLengthInBytes; i++)
        state[i] ^= data[i];
    KeccakPermutation(state);
}

void KeccakPermutationOnWords(UINT64 *state)
{
    unsigned int i;

    //displayStateAsWords(3, "Same, as words", state);

    for(i=0; i<nrRounds; i++) {
        //displayRoundNumber(3, i);

        theta(state);
        //displayStateAsWords(3, "After theta", state);

        rho(state);
        //displayStateAsWords(3, "After rho", state);

        pi(state);
        //displayStateAsWords(3, "After pi", state);

        chi(state);
        //displayStateAsWords(3, "After chi", state);

        iota(state, i);
        //displayStateAsWords(3, "After iota", state);
    }
}

#define index(x, y) (((x)%5)+5*((y)%5))
#define ROL64(a, offset) ((offset != 0) ? ((((UINT64)a) << offset) ^ (((UINT64)a) >> (64-offset))) : a)

void theta(UINT64 *A)
{
    unsigned int x, y;
    UINT64 C[5], D[5];

    for(x=0; x<5; x++) {
        C[x] = 0; 
        for(y=0; y<5; y++) 
            C[x] ^= A[index(x, y)];
        D[x] = ROL64(C[x], 1);
    }
    for(x=0; x<5; x++)
        for(y=0; y<5; y++)
            A[index(x, y)] ^= D[(x+1)%5] ^ C[(x+4)%5];
}

void rho(UINT64 *A)
{
    unsigned int x, y;

    for(x=0; x<5; x++) for(y=0; y<5; y++)
        A[index(x, y)] = ROL64(A[index(x, y)], KeccakRhoOffsets[index(x, y)]);
}

void pi(UINT64 *A)
{
    unsigned int x, y;
    UINT64 tempA[25];

    for(x=0; x<5; x++) for(y=0; y<5; y++)
        tempA[index(x, y)] = A[index(x, y)];
    for(x=0; x<5; x++) for(y=0; y<5; y++)
        A[index(0*x+1*y, 2*x+3*y)] = tempA[index(x, y)];
}

void chi(UINT64 *A)
{
    unsigned int x, y;
    UINT64 C[5];

    for(y=0; y<5; y++) { 
        for(x=0; x<5; x++)
            C[x] = A[index(x, y)] ^ ((~A[index(x+1, y)]) & A[index(x+2, y)]);
        for(x=0; x<5; x++)
            A[index(x, y)] = C[x];
    }
}

void iota(UINT64 *A, unsigned int indexRound)
{
    A[index(0, 0)] ^= KeccakRoundConstants[indexRound];
}

int LFSR86540(UINT8 *LFSR)
{
    int result = ((*LFSR) & 0x01) != 0;
    if (((*LFSR) & 0x80) != 0)
        // Primitive polynomial over GF(2): x^8+x^6+x^5+x^4+1
        (*LFSR) = ((*LFSR) << 1) ^ 0x71;
    else
        (*LFSR) <<= 1;
    return result;
}

void KeccakInitializeRoundConstants()
{
    UINT8 LFSRstate = 0x01;
    unsigned int i, j, bitPosition;

    for(i=0; i<nrRounds; i++) {
        KeccakRoundConstants[i] = 0;
        for(j=0; j<7; j++) {
            bitPosition = (1<<j)-1; //2^j-1
            if (LFSR86540(&LFSRstate))
                KeccakRoundConstants[i] ^= (UINT64)1<<bitPosition;
        }
    }
}

void KeccakInitializeRhoOffsets()
{
    unsigned int x, y, t, newX, newY;

    KeccakRhoOffsets[index(0, 0)] = 0;
    x = 1;
    y = 0;
    for(t=0; t<24; t++) {
        KeccakRhoOffsets[index(x, y)] = ((t+1)*(t+2)/2) % 64;
        newX = (0*x+1*y) % 5;
        newY = (2*x+3*y) % 5;
        x = newX;
        y = newY;
    }
}







void KeccakInitialize()
{
    KeccakInitializeRoundConstants();
    KeccakInitializeRhoOffsets();
}

/*
void displayRoundConstants(FILE *f)
{
    unsigned int i;

    for(i=0; i<nrRounds; i++) {
        fprintf(f, "RC[%02i][0][0] = ", i);
        fprintf(f, "%08X", (unsigned int)(KeccakRoundConstants[i] >> 32));
        fprintf(f, "%08X", (unsigned int)(KeccakRoundConstants[i] & 0xFFFFFFFFULL));
        fprintf(f, "\n");
    }
    fprintf(f, "\n");
}


void displayRhoOffsets(FILE *f)
{
    unsigned int x, y;

    for(y=0; y<5; y++) for(x=0; x<5; x++) {
        fprintf(f, "RhoOffset[%i][%i] = ", x, y);
        fprintf(f, "%2i", KeccakRhoOffsets[index(x, y)]);
        fprintf(f, "\n");
    }
    fprintf(f, "\n");
}
*/

void KeccakInitializeState(unsigned char *state)
{
    memset(state, 0, KeccakPermutationSizeInBytes);
}

/*
#ifdef ProvideFast576
void KeccakAbsorb576bits(unsigned char *state, const unsigned char *data)
{
    KeccakPermutationAfterXor(state, data, 72);
}
#endif

#ifdef ProvideFast832
void KeccakAbsorb832bits(unsigned char *state, const unsigned char *data)
{
    KeccakPermutationAfterXor(state, data, 104);
}
#endif

#ifdef ProvideFast1024
void KeccakAbsorb1024bits(unsigned char *state, const unsigned char *data)
{
    KeccakPermutationAfterXor(state, data, 128);
}
#endif

#ifdef ProvideFast1088
void KeccakAbsorb1088bits(unsigned char *state, const unsigned char *data)
{
    KeccakPermutationAfterXor(state, data, 136);
}
#endif

#ifdef ProvideFast1152
void KeccakAbsorb1152bits(unsigned char *state, const unsigned char *data)
{
    KeccakPermutationAfterXor(state, data, 144);
}
#endif

#ifdef ProvideFast1344
void KeccakAbsorb1344bits(unsigned char *state, const unsigned char *data)
{
    KeccakPermutationAfterXor(state, data, 168);
}
#endif
*/

void KeccakAbsorb(unsigned char *state, const unsigned char *data, unsigned int laneCount)
{
    KeccakPermutationAfterXor(state, data, laneCount*8);
}

/*
#ifdef ProvideFast1024
void KeccakExtract1024bits(const unsigned char *state, unsigned char *data)
{
    memcpy(data, state, 128);
}
#endif
*/
void KeccakExtract(const unsigned char *state, unsigned char *data, unsigned int laneCount)
{
    memcpy(data, state, laneCount*8);
}










